Linear-vision

That makes sense. There's a sense of being part of a shared event when watching linear TV, even if it's just a repeat of a popular movie. But with numbers steadily shifting to an on-demand future, Sky will have to think carefully about how it can keep value in more traditional TV watching.

"There's a question mark from me at some point in the future as to how long I need a Plus One channel," said Lewis.

"So when you have all of the films available on demand, and your main Sky premiere channel has got a Restart functionality, there will come a point where we see the viewing figures are so low on that channel.

"When our customers tell us they don't want it anymore then we'll probably close that channel down. But I think we're a long way off that."

Sky has a lot of curated on-demand movie packages which could easily be moved onto a linear format. For example, it will be bringing back another Harry Potter pop-up channel in the future.

Lewis says the length of time its pop-up channels will last will depends on the theme, but he hinted that we'll see them live for longer than they have in the past.

The first James Bond channel ran for just five weeks, but a recent Bond channel that ran in Germany had a two-and-a-half-month stretch. "And believe me, the last week of viewing figures were as big as the first," said Lewis.

He added: "Typically when we see the results at the end of it we go, 'We should have run it for a bit longer.'"